Finally got engine built won't run right
Thread Starter
Staging Lane
Joined: Mar 2011
Posts: 97
Likes: 0
Finally got engine built won't run right So i finally got my engine built and it's acting up on me , imagine that! Here's a list of what I did to it and the symptoms. I really appreciate any help!
Le2 combo
Comp RRs1.6
.30 over
32# injectors
New plugs and wires (msd)
Mail order tune
And full bolt ons
ive Also got a 255lph fuel pump I haven't put in yet. I built it about 6 months ago but just now got it back on the road. I had it sitting unde the barn as I didn't have time to finish it.
These are the symptoms, some of which might be normal, idk cause this is my first build!
Surging. Especially at idle. If you let it keep going the whole car will buck.
Backfiring if you rev it in neutral
Runs different when cold from when it warms up
When put in overdrive it will run smooth sometimes and at others it will Humm really loudly
Thanks in advance!
Le2 combo
Comp RRs1.6
.30 over
32# injectors
New plugs and wires (msd)
Mail order tune
And full bolt ons
ive Also got a 255lph fuel pump I haven't put in yet. I built it about 6 months ago but just now got it back on the road. I had it sitting unde the barn as I didn't have time to finish it.
These are the symptoms, some of which might be normal, idk cause this is my first build!
Surging. Especially at idle. If you let it keep going the whole car will buck.
Backfiring if you rev it in neutral
Runs different when cold from when it warms up
When put in overdrive it will run smooth sometimes and at others it will Humm really loudly
Thanks in advance!
Thread Starter
Staging Lane
Joined: Mar 2011
Posts: 97
Likes: 0
.575 228 110lsa cam and 3.42 gears (lower gears coming soon) I do have a ses light but it kicks on and off sproadically and it always has done that so Idk I've never been able to get a read off of it. And it seems like its runs it's best after you've been driving it maybe five minutes and its halfway warned up. After that it runs decent. Thanks for the quick reply by the way!
id get it dyno tuned, or maybe go over your tune. backfiring out the exhaust is usually a rich condition, excess fuel hitting the hot exhaust. with a cam youll experience a little bit of surge aslso, on mine i only experience it before like 2k though with very little throttle.
it would definetley hurt, gap to big or two small would lead to a weak spark not igniting the fuel correctly. Also check for exhaust/intake leaks. make sure all plug wires are on nice and snug. my cam surge use to buck real bad if i kept it on a slight throttle, does it run better cold or warm, cold engine isn't warmed up so your 02 sensor aren't operating. I'd just go over everything again real good. Also a little mor on the cam could help you gave us the lift of either exhaust or intake and lsa not to much to go off of haha.
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^what he said...........you dont need a dyno tune to drive it, somebody just has to work on the idle/part throttle stuff and it will be fine.........backfiring out the exhaust is usually too rich or too little timing, or a combo of both.........surging at idle is usually a lean condition.......sounds to me like the tune is FUBAR
whoever your tuner is that mail ordered it i'd contact them they should have no problem going over your tune again especially when you tell them how its acting, it isn't going to be perfect but it sure as hell shouldn't run that horrible
Thread Starter
Staging Lane
Joined: Mar 2011
Posts: 97
Likes: 0
im in middle tn though i frequent the huntsville al area. I think it was PCM for less? are yall confident it's in the tune? wouldnt maybe be valves need adjusting or some kind of sensor out? by the way i'm not sure what i'd do without yall haha!
we can never really be positive unless we were there in person, you could try adjusting your valves again i know i had mine to tight at first, loosened them up and my car fired right up(there wasn't enough oil in my lifters yet) some sort of scanner would tell you things so much better, could be o2s could not be o2s, could be exhaust leaks or intake leaks causing a lean condition whihch it then requires more fuel that it doesn't need which would be your backfires.... the surging though i'm almost positive is from the cam, do you still have the stock throttle body on it?
I'm sure you have already checked but a double check over all intake vacuum connections, sometimes vacuum leaks can manifest into several symptoms like that you have described; surging, bucking, and differential driving manners cold vs. warmed up. Even if all lines are connected you need to make sure none of the hard lines are cracked etc. If you find nothing there I would go through your valve adjustments once more.
you can try and readjust valves but i think its tune..........
use this procedure to do the valves
when exhaust valve is starting to open adjust your intake valve
when intake valve is starting to return from full lift do your exhaust valve
use this procedure to do the valves
when exhaust valve is starting to open adjust your intake valve
when intake valve is starting to return from full lift do your exhaust valve
